1. Field of the Invention
The present invention relates to a direct drive type washing machine which is capable of rotating an inner tub or a pulsator directly by a driving motor installed at the lower portion of an outer tub, and in particular to a direct drive washing machine which is capable of selectively rotating the inner tub through a clutch device coupling the driving force from the motor.
2. Description of the Background Art
As depicted in FIG. 1, the conventional direct drive washing machine includes a casing 1 having an opened upper portion, an outer tub 3 placed inside the casing 1 and supported by a plurality of supporting rods 2 (only one of which is shown) and for containing wash water, an inner tub 5 rotatively installed inside the outer tub 3 for receiving laundry therein, and a driving motor 9 installed at the lower portion of the outer tub 3 and rotating the inner tub 5 through an inter connecting tub shaft 6.
A pulsator 7, also called an agitator, is installed inside the inner tub 5 in order to form a wash water current.
In the conventional direct drive washing machine, the pulsator 7 and the inner tub 5 are rotated as one body by the driving motor 9, and a relative movement is generated between the wash water and the laundry and accordingly the laundry can be washed.
However, in the conventional direct drive washing machine, because washing is performed by rotating the inner tub 5 regardless of the kind and the load of clothes and the quantity of wash water, when the amount of clothes loaded is relatively small, the laundry is rotated in the same direction as the inner tub 5, and accordingly the relative movement between the water and the laundry may not be generated well and the washing efficiency may be lowered.
In addition, in the conventional direct drive washing machine, when washing is performed by rotating the inner tub 5, it may have a relatively larger inertia force than a type performing washing by rotating only a pulsator, and accordingly the load on the driving motor 9 is increased and the driving efficiency may consequently be lowered.